A novel haplotype of ‘Candidatus Liberibacter solanacearum’ found in Apiaceae and Polygonaceae family plants

Abstract

A previously unknown haplotype of the plant pathogen ‘Candidatus Liberibacter solanacearum’ (Lso) was found in cultivated carrots and parsnips in eastern Finland. That same haplotype was found in western Finland, over 300 km away, in the family Polygonaceae, the species Fallopia convolvulus (wild buckwheat) and Persicaria lapathifolia (pale persicaria) growing as weeds within carrot and parsnip fields. The infected plants, both apiaceous and polygonaceous, showed symptoms of foliar discolouration. This is the first report of Lso bacteria in plants of the family Polygonaceae. The finding that the polygonaceous plants infected with a previously unknown haplotype of Lso were growing among the apiaceous plants infected with Lso haplotype C suggests that these two haplotypes might be transmitted by different vectors. Phylogenetic analyses showed that the new haplotype, called haplotype H, is distinct from the previously characterized haplotypes and appears to have diverged early from their common ancestor. Multi-locus sequence analysis revealed four different sequence types (strains) within the haplotype H. These findings suggest that the haplotype H is likely to be endemic in northern Europe and that the genetic diversity within the Lso species is higher than previously assumed.

‘Candidatus Liberibacter solanacearum’ distribution and diversity in Scotland and the characterisation of novel haplotypes from Craspedolepta spp. (Psylloidea: Aphalaridae)

“…In phylogenetic analysis of the 50S rplJ/rplL gene region Cras1 variants and Cras2 formed a clade with the recently described haplotype H found in carrot in Finland 7 (Fig. 2).…”

“…Numbers on branches represent the percentage of iterations that support that clade (1,000 replicates). www.nature.com/scientificreports/ were designated as haplotype "H" and published within 24hrs of each other 7,8 . One haplotype was found in carrot, parsnip, and Polygonaceae weed species in Finland 7 and the other was found in B. cockerelli and Convolvulaceae 8 .…”

“…www.nature.com/scientificreports/ It might be necessary to sample plant material earlier in the season to detect Lso in these plants or to find Lso within root material as thus far we have only sampled aerial parts of C. angustifolium. The insect/ psyllid vector of haplotype H described from carrot in Finland is still to be determined but it is posited that it could also be a psyllid from the Aphalaridae such as Aphalara borealis, A. freji or A. maculipennis; inferred from their known plant host (P. lapathifolia) 7 . In our study we also observed that Aphalara spp.…”

“…Two haplotype Hs have been described due to concurrent publication, these two H haplotypes are genetically distinct and have different psyllid and plant hosts. The first haplotype H was described from symptomatic carrot in Finland and was also found in parsnip and native weed plants in the Polygonaceae (Fallopia convolvulus and Persicaria lapathifolia) 7 . The psyllid vector for this haplotype is currently unknown.…”

Assessment of Multilocus Sequence Analysis (MLSA) for Identification of Candidatus Liberibacter Solanacearum from Different Host Plants in Spain

“…DNAs for A, B, C and D haplotypes, provided by different research groups, were also used as controls. Finally, data from several isolates were obtained from databases and previous works [5,[7][8][9][14][15][16][17][18][19][20][21]. 5 Nettle plants Finland CLso U [7] 15-108 5 Trioza urticae Finland CLso U [7] Herbarium 51 5 Solanum umbelliferum USA CLso G [9] CLso 45-13 5 Potato/tuber USA CLso F [14] CLso ZC1 5 Bactericera cockerelli USA CLso B [15] CLso NZ1 5 Bactericera cockerelli New Zealand CLso A [16] PTSAPSY 5 Citrus sp.…”